Traditionally, an air cleaner assembly may consist of an outer body assembly and a filter element assembly that fits inside. Usually the element assembly contains the filter media, liners and some kind of wire cover to support the filter media, and provisions for sealing the housing or body by means of gaskets.
The body assembly usually contains both an air inlet and outlet as well as hardware to support and seal the element assembly to the body. Usually nuts and bolts attach to a center yolk assembly. Air cleaners which contain two elements (primary and safety) usually have a complicated center yolk assembly which contains hardware necessary to compress each element independently. Such a system is shown in U.S. Pat. No. 3,745,753. In such a system, it is essential that the housing seals be airtight, otherwise the usefulness of the filter is entirely lost.
In rough service, such as on earth moving vehicles and trucks, the housing may be subjected to considerable abuse which may cause it to be damaged and lose the integrity of the seals. Furthermore, inexperienced users may change filter elements and improperly reinstall in the housings, thereby allowing particulate matter to bypass the filter and destroy expensive machinery.
The present invention overcomes the problem of complicated yolk assemblies while simultaneously eliminating the need for airtight housing seals.
As shown in U.S. Pat. No. 3,745,753, a ramp (54) can be provided to induce a helical air flow within the housing to achieve centrifugal separation of the heaviest particulate matter. Unfortunately, this ramp requires the housing to have increased diameter which adds to the cost and the overall size of the unit.
The present invention provides an intake tube which assists in producing the helical flow necessary for centrifugal separation without increasing the overall size of the housing.